<!DOCTYPE html>
<html lang="zh-CN">
 <head>
  <meta charset="UTF-8" />
  <title> New Document </title>
  <meta name="Generator" content="NPP-Plugin">
  <meta name="Author" content="">
  <meta name="Keywords" content="">
  <meta name="Description" content="">
  <style>
	/* 这里是CSS代码 */
  *{margin:0px;padding:0px;}
  #nav{
    background-color:#eee;
    width:600px;
    height:40px;
    margin:0 auto;
  }
  ul{list-style:none}
  ul li{
    float:left;
    height:40px; 
    line-height:40px;
    text-align:center;
  }  
  a{text-decoration:none;color:#ccc;display:block;padding:0 10px;}
  a:hover{color:#fff;background-color:#aaa;}
  </style>

 </head>
 <body>
 <div id="nav">
   <ul>
    <li><a href="#">首页</a></li>
    <li><a href="#">栏目1</a></li>
    <li><a href="#">栏目2</a></li>
    <li><a href="#">栏目3</a></li>
   </ul>
 </div>
 </body>
</html>